Recently it has been found that sanitary napkins containing absorbent layers having thermoplastic material have certain advantages over such napkins utilizing only conventional cellulosic material as an absorbent. The presence of thermoplastic material adds resiliency to the absorbent and also tends to prevent the collapse of capillaries of cellulosic material when the two materials are blended together. Examples of patents which discuss the utilization of thermoplastic material in conjunction with cellulosic material for sanitary appliances are: U.S. Pat. Nos. 4,082,886 and 4,129,132 issued to George A. M. Butterworth et al; 3,976,074 issued to Harry G. Fitzgerald et al; 4,054,141 issued to Julius Schwaiger et al; 4,047,531 issued to Hamzeh Karami; 3,545,441 issued to Gunnar Gravdahl and 4,219,024 issued to Donald Patience et al.
The above patents also describe the concept of sanitary napkins with multilayer absorbents.
It has been recently determined that sanitary napkins with multilayer absorbents in which the layers are formed by folding provide increased comfort not only in the folded areas, but also with regard to resistance to permanent distortion and resiliency. These features are particularly enhanced when thermoplastic fibers are utilized throughout the folded absorbent batt. When thermoplastic fibers are present, the resistance to permanent compressibility is enhanced because of the presence of each individual fold. Bearing this in mind, a napkin in which an absorbent batt with thermoplastic fibers has been folded repeatedly upon itself should be substantially more comfortable than one without this feature.
Where thermoplastic fibers have been utilized, however, there is generally a decrease in total absorbent capacity, especially when the fibers are present in amounts sufficient to add resiliency.